RICHMOND, Va., Sept 3 (Reuters) - A federal court jury ended a second day of deliberations without reaching a verdict on Wednesday in the trial of former Virginia Governor Robert McDonnell, who is accused of accepting bribes from a businessman to endorse his healthcare products.

A 14-count indictment charges that McDonnell and his wife, Maureen, who have been living separately during the trial and say they are estranged, received $177,000 in sweetheart loans and lavish gifts from dietary supplement entrepreneur Jonnie Williams Sr.

In exchange, the indictment says, McDonnell and his wife conspired to use the governor's office to promote Williams' company and its leading brand, the anti-inflammatory medication Anatabloc.

If convicted on all charges, the McDonnells, both 60, could be sentenced to 20 years in prison and be ordered to pay hefty fines.

The U.S. District Court jury of seven men and five women met for about 7-1/2 hours on Wednesday before the judge dismissed the panel for the day, ordering the jurors to return to court to resume deliberations on Thursday morning.

The jurors deliberated on Tuesday for 5-1/2 hours after receiving the case.

In outlining the chief issues to be decided in the trial, U.S. District Judge James Spencer told jurors that those involved in a conspiracy did not have to be successful for the conspiracy to have occurred.

He also instructed them that Maureen McDonnell, even though a private citizen in her role as first lady, could still be convicted of acting as a conspirator.

Prosecutors have argued that McDonnell, a Republican whose term ended in January, knowingly took loans and gifts from Williams but was trying to distance himself from misconduct by blaming his wife.

The defense has countered that prosecutors must show that Williams received a significant benefit from his gifts and loans. They also argued that the couple's marriage was so frayed that the McDonnells could not have conspired together with Williams.

Robert McDonnell testified that he performed only routine courtesies for Williams, the former chief executive of Star Scientific Inc, as he would for any other businessman in his state. (Reporting by Gary Robertson; Editing by Ian Simpson, Steve Gorman and Peter Cooney)